FILE - In this Oct. 18, 2011, file photo, then-Secretary of State Hillary Rodham Clinton checks her Blackberry from a desk inside a C-17 military plane upon her departure from Malta, in the Mediterranean Sea, bound for Tripoli, Libya. The private email server running in Clintons home basement when she was secretary of state was connected to the Internet in ways that made it more vulnerable to hackers, according to data and documents reviewed by The Associated Press. (Kevin Lamarque/Pool Photo via AP, File)

WASHINGTON (AP) – Hillary Clinton has been interviewed Saturday by the FBI about her use of a private email server while she was secretary of state.

Clinton campaign spokesman Nick Merrill says in a statement the voluntary interview with federal agents took place Saturday.

The interview was not unexpected and does not suggest that Clinton or anyone else is likely to face prosecution. Legal experts view criminal prosecution as exceedingly unlikely. The interview may indicate that the Justice Department’s yearlong probe is drawing to a close.

Still, it’s awkward for Democrats to have FBI agents question Clinton mere weeks before their party formally nominates her for president.

Sources confirm to CBS News that the investigation is in its final phase and interviewing Clinton was one of the last steps before concluding the investigation and submitting recommendations on whether charges should be filed.

The meeting, which lasted approximately three-and-a-half hours, took place at FBI headquarters in Washington, D.C., according to a campaign aide.

Federal investigators have already interviewed close aides to the former secretary of state, including Huma Abedin, who faced questioning in April at the FBI’s Washington field office.